(a) Field of the Invention
This invention relates to a portable furnace for assaying ore samples and more particularly, but not by way of limitation, to a light weight, portable furnace using a gas blow torch for heating a crushed ore sample inside a cupel and assaying the sample in the field or laboratory for a rare metal.
(b) Discussion of Prior Art
Heretofore, prospectors and miners have faced a problem of positively identifying an amount or a type of rare metal in a rock specimen. Two methods have been used to test rock specimens in the field. They are chemical tests and fire tests. Chemical tests involve the use of acids and reagents to cause a color change or other reaction in hope of revealing the contents in the specimen. Within the area of chemical tests are leaching tests, which mimic the last stages of gold mining on a small scale to produce a pure metal extract. Fire tests involve heating the rock specimen with a flame to produce a color change, sublimation, or other effect, which gives a clue to the contents in the specimen.
The tests mentioned above are attempts to answer the “What is it?” question, know as a qualitative test, and the “How much is there?” question, known as a quantitative test. Until now, only the above mentioned leach test can answer both of these questions in the field.
While the above testing methods have proven effective over the years, they require bulky, heavy and fragile equipment and knowledge of chemistry. Inclement weather and remote, rough terrain can make the use of this equipment in the field difficult. Therefore, prospectors, miners and geologists have resorted to taking rock samples to laboratories for assaying. The transporting of the samples involves transportation costs, added labor and time wasted, which can be used more profitably in the field.
Also, while a laboratory assay can be a reliable method to answer the qualitative and quantitative questions, it is expensive and time consuming. Further, the cost of a furnace capable of smelting and refining ore samples is prohibitive for an individual miner or prospector. Although there are small, table top furnaces available on the market, they require electrical power or natural gas, which limits their use to the laboratory. Also, their weight further prohibits these types of furnaces in the field.
In an attempt to solve the above assaying of ore sample problems in the field, some assay operators use small portable oxygen/acetylene gas welding equipment along with a cupel or crucible. The major problem with this approach is the time involved. These type of assays often take more than an hour to perform and operator fatigue becomes a factor long before the process is complete.
The subject invention provides a unique portable, light weight furnace for assaying different types of rare metal ore samples in the field and eliminating the need of the above mentioned assaying equipment.